Evening Grosbeak

A heavyset finch of northern coniferous forests, the Evening Grosbeak adds a splash of color to winter bird feeders every few years, when large flocks depart their northern breeding grounds en masse to seek food to the south. The yellow-bodied, dusky-headed male has an imposing air thanks to his massive bill and fierce eyebrow stripe. The female is more subtly marked, with golden highlights on her soft gray plumage. This declining species is becoming uncommon, particularly in the eastern United States.

Measurements

Both Sexes

Relative Size

About the size of a Northern Cardinal, but more compact and thicker bodied; smaller than a Steller’s Jay or Blue Jay.

Other Names

Gros-bec errant (French)

Pepitero norteño (Spanish)

Cool Facts

The Evening Grosbeak is a songbird without a song—that is, it does not seem to use any complex sounds to attract a mate or defend its territory. It does have a small repertoire of simple calls, including sweet, piercing notes and burry chirps.

With their enormous bills, Evening Grosbeaks can crush seeds that are too large for Common Redpolls and Pine Siskins to open. These smaller birds often seek out the grosbeaks and glean the food scraps they leave behind.

Evening Grosbeaks are irregular (or “irruptive”) winter migrants. Some years these spectacular finches show up at feeders far south of their normal winter range—providing a treat for backyard bird watchers. By joining Project FeederWatch you can keep track of visits by these and other winter birds—and the data you record will help scientists keep track of bird populations.

Though they’re ferocious seed-crackers in the wintertime, in summer Evening Grosbeaks eat insects such as spruce budworm, a serious forest pest. The grosbeaks are so adept at finding these tiny caterpillars that the birds often provide a first warning that a budworm outbreak has begun.

In the mid-1800s, Evening Grosbeaks were uncommon to rare east of the Rockies, but then they began moving eastward with each winter migration, reaching Rhode Island in the winter of 1910–1911. By the 1920s they were considered a regular winter visitor in New England. This eastward expansion may be related to the growing number of ornamental box elders, which provide a steady food supply for the grosbeaks.

The oldest Evening Grosbeak on record was at least 16 years, 3 months old.

Habitat

Forest

Evening Grosbeaks breed in mature and second-growth coniferous forests of northern North America and the Rocky Mountains, including spruce-fir, pine-oak, pinyon-juniper, and aspen forests. Less commonly, they nest in deciduous woodlands, parks, and orchards. They breed as far south as Mexico at 5,000–10,000 feet of elevation in pine and pine-oak woodlands. In winter Evening Grosbeaks live in coniferous forest and deciduous forest as well as in urban and suburban areas. When wintering in urban environments they are most abundant in small woodlots near bird feeders.

Food

Seeds

In summer, Evening Grosbeaks eat mostly invertebrates such as spruce budworm larvae, caterpillars, and aphids. They also eat a wide variety of seeds—including those of maple, box elder, ash, cherry, apple, tulip poplar, elm, pine, dock, bindweed, and goosefoot—and small fruits, such as ash fruits, cherries, crabapples, snowberries, hawthorn fruits, Russian olive fruits, and juniper berries. They may manipulate fleshy fruits such as cherries in their bills to remove the skin and flesh before cracking and swallowing the seed. Evening Grosbeaks typically feed at the tops of trees and shrubs, but you may see them come to the ground for fallen fruits and seeds or capture aerial insects in flight. They also eat the buds of maple, elm, willow, oak, aspen, and cherry, and drink maple sap by breaking off small maple twigs.

Nest Description

The female does most of the nest building, collecting materials from the ground and breaking twigs from trees. She builds a flimsy, saucer-shaped nest of small twigs and roots lined with grasses, fine rootlets, lichens, or pine needles. The nest measures about 5 inches across and 5 inches high, with the inner cup measuring about 3 inches across and 1 inch deep.

Behavior

Ground Forager

Evening Grosbeaks are social birds that forage in flocks in winter and break off into small groups or pairs during the breeding season. Evening Grosbeaks show little aggression toward one another throughout the year. At winter feeders males may drive females and younger males away, but they do not defend feeding territories during the breeding season—probably because their food sources are often extremely abundant in local patches. During the nesting season they form monogamous pairs, after courting quietly without any elaborate song or display. Breeding birds tolerate other birds nearby but occasionally chase away species such as phoebes, Hairy Woodpeckers, American Robins, and Brown-headed Cowbirds. At feeders, Evening Grosbeaks are often accompanied by redpolls and Pine Siskins that glean the food scraps they leave behind.

Conservation

Evening Grosbeaks are numerous and widespread, but their populations have dropped steeply in recent decades according to the North American Breeding Bird Survey—particularly in the East. Their irruptive nature makes it hard for large-scale surveys to make precise estimates, but the Breeding Bird Survey suggests a decline of at least 2.3 percent per year since 1966 (a cumulative drop of at least 64 percent in that time). Partners in Flight estimates the global breeding population is 4.1 million, with 71 percent spending some part of the year in the U.S., 57 percent in Canada, and 5 percent in Mexico. They score a 12 out of 20 on the Continental Concern Score and are on the 2014 State of the BirdsWatch List, which lists species most in danger of extinction without significant conservation action. A 2008 study of Project FeederWatch data found that the grosbeak’s winter range had contracted and numbers had declined. Evening Grosbeaks were reported at only half the number of sites, and flock sizes were down by 27 percent, in the early 2000s compared with the late 1980s. Evening Grosbeaks were rare in eastern North America until the mid-nineteenth century, when they began expanding eastward, possibly aided by the spread of box elders (which were increasingly being planted in cities), or possibly to outbreaks of forest insects such as spruce budworm. By the 1920s they were regular winter visitors in New England, and their range expansion peaked in the 1970s and 1980s. Recent declines may be due to logging and other development in the boreal forests of northern North America; to disease outbreaks such as salmonella, West Nile virus, and House Finch eye disease; or to reduced numbers of spruce budworm and other forest insects, in part due to aerial spraying by the U.S. and Canada. As climate change alters the landscape over the next century, balsam fir is expected to recede from New England, and Evening Grosbeaks may disappear from this region.

Migration

Irregular migrant. When cone crops in northern coniferous forests are poor, Evening Grosbeaks “irrupt” in fall and spend the winter far south of their normal range. These irruptions formerly happened every 2–3 years in the eastern United States but have become less frequent, particularly in the East, since the 1980s. Western subspecies migrate to lower elevations for the winter.

Backyard Tips

Although they may not visit your backyard every year, Evening Grosbeaks show up irregularly at feeders during the winter. They eat sunflower seeds and are also attracted to the seeds, berries, and buds of trees and shrubs—especially maples. They are fairly large birds and they often travel in sizeable flocks, so they often use platform feeders as opposed to tube feeders. Find out more about what this bird likes to eat and what feeder is best by using the Project FeederWatch Common Feeder Birds bird list.

Find This Bird

It’s hard to predict where in the western and northeastern U.S. Evening Grosbeaks will show up in any given winter. When they move into an area, they’re very likely to show up at platform feeders offering sunflower seeds, particularly near forested areas at higher elevations. Out in the woods, you’ll have better luck finding a flock if you listen for their running patter of call notes, which can be sweet, burry, or sharp. In summer you’ll need to be in northern North America or in the mountains of the West, where Evening Grosbeaks breed in coniferous forests. At this time they are harder to find as they forage and nest high in trees, travel in smaller groups, and make less noise.